The invention relates to a method for exchanging shears of a shears device used for cutting strips or sheet metal to length in a rolling or transport line, in particular, on a rolling table, which device has blade holders, one being positioned above and one being positioned below the strip, which blade holders are guided by means of holding elements. The invention also relates to a device for performing the method.
Stationary or flying shears are known which can be moved in and out of the rolling line or rolling table but only when the rolling table is not occupied in the area of the shears or other separating device by the strips or sheet metal to be cut.
Shears which are permanently and fixedly arranged in the rolling or transport line are in many cases considered an obstruction because they cover a portion of the rolling table and thus make a control action in this area more difficult. Also, the shears positioned in the rolling or transport line can present a hindrance to the running of the strip when introducing the leading edge of the strip. However, they may also represent a disturbance factor during further running of the strip, in particular, when inspections or maintenance work has to be performed on the shears or the area of the rolling table covered by the shears. Overall, with shears positioned stationary in the area of the rolling or transport line the accessibility of a rolling table area is impaired and, possibly, the running of the strip is disturbed.
U.S. Pat. No. 3,561,311 describes a shearing device with a pair of hollow shafts for receiving axially movable rods with a cutting blade attached thereto that can be positioned within a blade drum rotatable with the hollow shaft. Usually, the blades are secured in a locking position. When the rods are moved by a selective displacement, the blades are moved toward each other to carry out a cutting or shearing action for rolled material passing between the blade drums. After each cut, the shearing blades are retracted into a rest position by brake means in order to prevent continued movement of the blades.
U.S. Pat. No. 3,638,523 shows a shearing machine with interchangeable blade-holders wherein the blade holder can be laterally removed together with the blades from the machine. The movable and the stationary blade holders have adjustment wedges such that each wedge within the blade holder can independently adjust clearance at the blade holder slide guide and the clearance between the moveable and the stationary blades. In this way, an adjustment operation of the clearances after mounting of the blade holder is eliminated.
U.S. Pat. No. 3,895,549 discloses a method and device for cutting the leading and trailing ends of steel strip by means of two pairs of blades. The blades are mounted on the periphery of two drums. Each drum has a blade for the leading end and a blade for the trailing end. The blades are positioned such that the blade for the front end cut is positioned not more than 180 degrees behind the blade for the trailing end cut. The rollers are rotated in different directions in order to be able to cut each end of the strip. As a result of this method, the ends of the strip can be improved significantly in order to achieve proper passing of the strip through the hot finishing rolling device. Also, the shearing device requires less energy.
U.S. Pat. No. 4,470,331 discloses a scroll-type slitting machine having upper and lower arbors, each having a plurality of mating rotary cutting members. A movable housing rotatably supports first ends of the upper and lower arbors. A fixed housing rotatably supports opposite ends of the upper and lower arbors. A mechanism for vertically adjusting the arbors relative to the other is provided. A pinion stand is mounted external and adjacent to one of the housings. Upper and lower intermeshing, synchronizing gears are rotatably mounted within the pinion stand. Upper and lower torque-transmitting couplings extend between and operatively join the upper and lower synchronizing gears to the upper and lower arbors, respectively. They permit relative movement between the arbors.
U.S. Pat. No. 4,507,994 describes a device for monitoring the tractive force generated by a cylinder-piston assembly on a member to be moved thereby. The device has a spring that is mounted between the cylinder assembly and the member to be moved such that the force generated by the cylinder-piston assembly is transmitted to the spring for moving a first portion relative to a second portion thereof. An actuatable switch has a first switching element mounted for movement with the first portion of the spring and a second switching element fixedly mounted to the second portion of the spring. The two switching elements actuate the switch when a predetermined path of travel of the first portion of the spring is exceeded.
U.S. Pat. No. 4,608,895 discloses a pair of rotary dies with lands having coacting cutting edges which cut blanks of material from a web passing between the rotating dies. To provide a clean cut and improved squareness of the cut ends, a side face of the land adjacent the cutting edge has a positive rake. To ensure that the cutting edges can be brought into coacting relationship to produce a clean cut, they are located and arranged on the dies so that they can be varied and adjusted axially and in rotary phase relative to each other. A die stand for positioning, adjusting and driving the rotary dies is provided. A method for making negative electrode cylinders for producing the rotary dies by hardening, grinding and electric discharge machining blank cylinders of tool steel, is also disclosed.
U.S. Pat. No. 4,922,778 describes an apparatus for cutting metal sheet wherein a pair of hollow shafts are mounted in a housing for angular movement relative thereto. The hollow shafts have hollow bores whose axes are eccentric to the axes of the hollow shafts, respectively. A pair of holder shafts are rotatably fitted in the hollow bores, respectively. A pair of circular cutting blades are concentrically mounted on projecting forward ends of the holder shafts, respectively, for rotation with the hollow shafts. When the holder shafts are rotated to rotate the cutter blades, the cutter blades cooperate with each other to cut a metal sheet passing between the cutter blades.
U.S. Pat. No. 5,363,731 describes an apparatus for regulating and adjusting powered rolls for conveying metal plates supported in tubular crossbeams that is always reliable in operation and provided with a simple configuration protection from rust deposits. The apparatus is suitable especially for shears for edge trimming and/or for longitudinal or transverse division of the plates. The apparatus has regulation elements as wedges which are displaceably arranged within a bearing bracket and are in operational connection with the adjustment elements.
U.S. Pat. No. 5,673,603 shows a device for cutting to shape advancing material webs made of fibrous materials. The device has a rotatingly driven shape cutting roller and a rotatingly driven counter cutting roller. The shape cutting roller has a shape cutting edge and the counter cutting roller a smooth cylinder surface. Both rollers are mounted in a machine frame by means of pivot bearings, and the distance between the axes of the rollers is adjustable. One of these machine frame parts is held on an adjustable wedge-shaped guide for adjusting the distance between the axes of the rollers.
U.S. Pat. No. 6,026,722 discloses a device for cutting electric battery plates and has two rollers, between which a metal strip passes. The metal strip has a row of holes running down the center, separated by bridges. The lower roller is provided with means for removing cut-away pieces. A disk is mounted on the lower roller. Lugs project radially from the disk to pull the strip along. Cutter plates are mounted on the upper roller. The cutter plates are provided with blades that cut the strip and the bridges transversely to yield plates with their respective tabs. Inserts are provided under the cutter plates.
U.S. 2001/0020407 A1 describes a high-speed shearing arrangement for transversely cutting rolled strip with knife carriers that can be driven in rotation and are arranged in pairs opposite each other. The knife carriers are arranged with a fixed distance between them on both sides of the strip in a common shear cassette. The shear cassette is mounted within an outer frame and is provided with a lifting device for raising or lowering it within the outer frame. In a method for operating the shearing arrangement, the two knife carriers are moved into a horizontal position for allowing the strip end to enter or travel through, and the shear cassette is moved within the outer frame into a raised transfer position.
U.S. Pat. No. 6,295,909 discloses an apparatus for cutting metal sheet having two rotatable drums, wherein the metal sheet passes between the drums for cutting. Each of the drums has a cutting blade moved into and out of cutting position by an axial actuator rod. The cutting blade has two sets of rollers bearing against one of a pair of profiled side surfaces of the axial actuator rod.
U.S. Pat. No. 6,370,998 discloses upper and lower rotating drums having shearing blades that are supported by a bearing frame via eccentric sleeves. Only the upper rotating drum is rotated by a drive motor, while the eccentric sleeves are rotated by a drive motor, so that the rotating drums can approach one another and move away from each other. Interlocking gears are fixed to shaft end portions of the rotating drums to permit interlocking of the rotating drums when these drums approach. Oldham's couplings are interposed between the interlocking gears and timing gears to rotate the rotating drums constantly and synchronously.
German patent document 1 436 909 describes a machine for cutting, upsetting or similar processing steps of web material sheet material, in particular, for use in connection with corrugated cardboard where the material is supplied continuously to the processing tools. The machine is provided with at least two different adjustable sets of rotating tools, such as cutting or upsetting tools, and with a device provided with a pressure medium cylinder which moves the first tool set into a working position and the other into a rest position, respectively. The tool sets, before they reach their working position, are already rotated at the desired rotational speed.